[s-cars] Brake Rotor with Big Reds(OOOPPPSSS)

[Theodore Chen]

depends on whether you're comfortable with that.  i saw a race car 
that had a brake rotor fail catastrophically.  a large chunk of 
rotor shot out through the fender, and the remaining section 
jammed against the caliper, destroying it and locking up the wheel.
the car crashed into the wall and took out all the body work on 
that side of the car and trashed the suspension.

let's distinguish between cracks and heat checking.  it's normal for
rotors to develop tiny surface cracks from hard use.  if you have small 
cracks that are more than a half inch long, or the cracks go deep enough
to reach the interior of the rotor, consider replacing the rotor.

i don't think drilled rotors are worth it.  drilling and slotting are
intended to allow gases and ablated pad material to escape, but with
modern race pads, the benefits are minimal.  the cooling effect of
drilled rotors is very small.  drilling a rotor drastically shortens
its life unless it's designed to have holes in it, like porsche's rotors.

rotors are already under tremendous stress from compression by the 
brake calipers, friction loading of the pads against the rotors, and 
centrifugal forces.  they are also subjected to large and abrupt thermal
gradients.  drilling removes material from the rotor, concentrates stress 
in the area of the holes, and creates stress risers (due to imperfections 
in machining) right where you just concentrated stress.  so they crack
faster than solid rotors.

-teddy

--- Keith Maddock <keith.maddock at gmail.com> wrote:
> LOL :)  it's really not even a problem to run them at the track until
> they crack - as long as you've brought spareparts with you (or have a
> line on a local garage who can hook you up with some replacements...) 
> Just  take it easy once your brakes start rumbling, or you'll go
> through your brake pad$ in a hurry :-D
> 
> Cheers,
> Keith
> 
> On 5/18/05, Joe Pizzimenti <joe.pizzimenti at gmail.com> wrote:
> > Not really a big deal, especially if you track the car or have a habit
> > of Krasusking it on a regular basis on the street.
> > 
> > Keep an eye on them and it probably isn't a great idea to run slightly
> > cracked rotors on the track.  Little stuff turns into big stuff out
> > there.
> > 
> > Joe
> >
> 

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